Governor for fuel injection pump



Nov. 19, 1968 v. D. RoosA GOVERNOR FOR FUEL INJECTION PUMP A, Winn-... JQQ QQ 5 Sheets-Sheet 1 INVENTOR VERNON D. ROOSA ATTORNEYS Nov. I19, 196sv D- ROOSA 3,411,365

GOVERNOR FOR FUEL INJECTION PUMP 'Filed Nov. 1, 1965 5 Sheets-Sheet 2 FG 3 Y l INV TOR.

VERNON OOSA ATTORNEYS Nov. 19, 1968 v. D. RoosA 3,411,355

GOVERNOR FOR FUEL INJECTION PUMP Filed Nov. l. 1965 3 Sheets-Sheet 3 Illwww

1N VENTOR. VERNON D. ROOSA ATTORN EYS United States Patent O 3,411,365GOVERNOR FOR FUEL INJECTION PUMP Vernon D. Roosa, The Hartford MachineScrew Company, P.O. Box 1440, West Hartford, Conn. 06102 Filed Nov. 1,1965, Ser. No. 505,840 10 Claims. (Cl. 73--494) ABSTRACT OF THEDISCLOSURE A fuel pump governor of the type utilized in fuel injectionsystems for delivering measured charges of fuel to the nozzles of anassociated internal combustion engine. Said governor comprising a gear,one end of which is segmented to provide a plurality of angularly spacedslots around the periphery thereof, a cap member engaging the segmentsof said gear for rotation therewith, a plurality of weights mounted insaid slots for pivotable movement during rotation, whereby said gear andcap members form a cage for guiding the weights in said pivotablemovement.

This invention relates to an improved governing means for fuel pumps ofthe type utilized in fuel injection systems for delivering measuredcharges of fuel to the nozzles of an associated internal combustionengine.

An object of this invention is to provide an improved governor for fuelpumps of the type referred to which is capable of more effective speedregulation over a wider speed range and which is arranged to be mountedin an improved manner in the fuel pump.

Another object of this invention is to provide a governor which can bemounted in the fuel pump to rotate at a higher speed than the rotorthereof and which is of simplified construction whereby it can befabricated and assembled in an economical and convenient manner.

A more specific object of this invention is to provide a combinedgovernor drive and cage construction.

Other objects will be in part obvious and in part pointed out more indetail hereinafter.

The invention accordingly consists in the features of construction,combination of elements and arrangement of parts which will beexemplified in the construction hereafter set forth, and the scope ofthe application of which will be indicated in the appended claims.

In the drawings:

FIG. 1 is a longitudinal cross-sectional view, partly broken away, of afuel injection pump embodying the present invention;

FIG. 2 is an enlarged fragmentary sectional view taken along line 2-2 ofFIG. l;

FIG. 3 is a fragmentary sectional view taken along line 3 3 of FIG. 2;

FIG. 4 is an elarged cross-sectional view taken along line 4-4 of FIG.l; and

FIG. 5 is an exploded perspective View of the governor assembly of thisinvention.

Referring now to the drawings in detail, in which like numerals refer tolike parts throughout the several tigures, a pump exemplifying thepresent invention is of the type now commercially available forsupplying fuel charges to an associated internal combustion engine. Thepump comprises an external housing or casing having an axial bore oropening 12 rotatably supporting a pump rotor or distributor 14.

At the right end of the housing 10, as viewed in FIG. 1, there ismounted a vane-type fuel supply or transfer pump 18 driven by the rotor14 and having an inlet port 16 and a discharge port 17. A diagonal inletpassage 20 delivers fuel to the transfer pump 18 from an inlet pipe3,411,365 Patented Nov. 19, 1968 ICC 22 which is connected to a fuelsupply reservoir. The transfer pump delivers fuel under pressure throughan outlet passage 24 in the housing 10 to an air separator 26 fromwhence the fuel ows through a passage 28 (FIG. 2) in the housing 10 to alongitudinal bore 30 in the housing. A slideable spring biased pressureregulating valve 32 (FIG. 3) is mounted in the bore 30 for regulatingthe output pressure `of the pump 18. Regulating valve 32 delivers fuelto the metering valve 34 at a pressure correlated with the speed of thedriving engine through conduit 33 and returns excess fuel to thetransfer pump inlet conduit 20 through conduit 35.

The high pressure charge pump generally denoted by the numeral 40 isformed by a transverse bore 42 in rotor 14 in which are slideablymounted a pair of opposed plungers 44. The outer ends of the plungersengage against shoes 46 which are slideably mounted in transversepassages 48 formed by the bifurcated end 47 of a separable drive shaft60 aligned with bore 42. As shown in FIG. 4, the bifurcated end of driveshaft 60 also provides a pair of flat opposed shoulders which engagecornplementary shoulders 45 on the rotor 14 to drive the same.

Surrounding the rotary member 14 is a generally circular or ring-likecam ring 50 preferably constructed -of hardened steel which encirclesthe rotor 14 in the plane of revolution of the plungers 44 and ismounted for angular adjustment within an annular bore 49 in the pumphousing. The cam has a plurality of pairs of diametrically opposedinwardly extending cam lobes 52 which are adapted to actuate theplungers 44 inwardly simultaneously for discharging fuel from the pump,it being understood that the rollers 43 and the roller shoes 46 aredisposed -between the plungers 44 and the cam 50 whereby `the rollers 43act as cam followers for translating the cam contour into thisreciprocal movement of the plungers 44. The C-shaped ring 56 secured tothe charge pump by a screw fastener 58 (FIG. 4) provides an adjustableouter resilient top for the roll shoes 46. A seal 62 is provided toprevent leakage of fuel into or out of between the shaft 60 and thehousing 10.

Upon rotation of the drive shaft 60, the transfer pump 13 and the chargepump 40 are rotated to supply measured charges of fuel under pressure toa plurality of fuel pump outlets 84 having suitable connections with thefuel injection nozzles of an associated engine. During the outward orintake stroke of the plungers 44 fuel is delivered to the charge pumpfrom the metering port 41 by a passage 66 in the housing 10 and adiagonal passage 68 in the rotor 14. During the inward or dischargestroke of the plungers 44 fuel is delivered under high pressure by anaxial passage 76 to a pressure-operated delivery valve 77 and agenerally radially extending distributor passage 78 adapted forsequential registration with a plurality of angularly spaced radialdelivery passages 63 in fluid cornmunication respectively with aplurality of pump outlets 84, only one of which is shown for convenienceof illustration. It is to be noted that a one-way check valve 68aprevents reverse flow through inlet passage 68 during the dischargestroke of charge pump 40.

As shown in FIG. 4, the housing 10' has a transverse bore in which anautomatic injection timing advance plunger 102 is reciprocably mounted.A passage 104 (FIG. 1) delivers regulated transfer pump outlet pressurefrom air separator 26 to bore 100. In the illustrated design, theplunger 102 includes a pilot valve 105 positioned inV a chamber 105, oneend of which is in continuous communication with housing passage 104through passage 108 in plunger 102. A one-way valve is positioned inpilot valve 105 to prevent the reverse flow of fluid through the passage108 as a result of intermittent pulsations of force imposed on theplunger 102 due to the operation of the charge pump.

Pilot valve 105 is also provided with an annular land which is axiallyshiftable over port 111 in the plunger 102. Port 111 communicatesthrough passage 112 to a chamber 113 formed in the end of transversehousing7 bore 100 to deliver fuel under pressure thereto lwhen annularland 110 of the pilot valve is moved to the left to providecommunication between passage 108 and port 111 via annulus 107. lnasmuchas the transfer pump pressure is a function of engine speed, thebalanced position assumed by the pilot valve is determined by theequilibrium between the forces imposed thereon by the transfer pumppressure and the spring 109, an end of which engages screw 103. This, inturn, determines whether the port 111 communicates with annulus 107 toreceive additional fuel from the transfer pump (and hence shift plunger102 to the left to advance the time of injection) or the port 111communicates with passage 114 to dump a portion of the fuel trapped inthe chamber 113 into the pump housing through passage 114 to permit theplunger 102 to move to the right.

An arm 115 having a cylindrical body 116 mounted in a complementaryradial bore 118 in the plunger 102, and an integral head 120 closelyreceived within a bore 101 of the cam ring 50 which serves as a sockettherefor connects the plunger 102 and the cam 50. A snap ring 124 seatedin an annular groove in the connector 115' prevents excess axialmovement of the connector toward the cam ring.

In accordance with this invention, a governor 31 of simplified andimproved construction is disposed within a chamber formed in the end capy of the housing 10 as shown in FIG. l. A driving gear 65 secured to thedrive shaft 60 engages the gear 64 to provide a step-up drive for-driving the governor. This step-up drive arrangement serves to amplifythe speed of the rotation of the governor, by say 21/2-4 times, relativeto that of the pump to permit the governor to be miniaturized.

An apertured sleeve 142, which projects into the governor chamber, isnonrotatably secured with respect to the housing 10 and provides a stubshaft on which the gear 64 is journaled to support the governor 31 forrotation.

As best seen in FIG. 5, an important feature of this invention is thatthe governor gear 64 is segmented at one end so that it also serves asthe inner cage for the governor 31. The projecting V-shaped gearsegments shown as being six in number, are spaced apart to form aplurality of rectangular pockets or slots 152, each of which may receivea governor weight 154 having a generally trapezoidal shape. The governorweights 154 are notched at 156 to provide inwardly extending fingers158. A control member, or metering valve, 34 is slideably mounted foraxial movement within the sleeve 142, has a thrust washer 160 at itsinner end in engagement with the fingers 158 of the governor weights154. The governor weights are adapted to pivot on the apex or corners163 thereof in the outer corner 162 of the cap member 148 which,together with gear 64, serve to form the complete cage assembly for thegovernor weights. The center of gravity of the weights 154 is at theright of the apex 163, as viewed in FIG. 1, with the result that as thecage formed by the gear 64 and the cap member 148 is rotated, theweights will tend to pivot outwardly responsive to centrifugal forceabout the apexes 163 thus applying an axial force through the ngers 158and the thrust washer 160 to the metering valve 34. The reaction forceis transmitted through the apexes 162 of the cap member 148, the centralhub 149 of which engages the thrust washer 146 of the adjusting screw144 `which is threaded into an aperture of the end wall of the governorchamber.

The parallel surfaces of the gear segments 150 defining the rectangularslots 152 serve to positively guide the pivotal movement of the weights154 and to rotate the same as the gear 64 rotates.

In order to avoid any sticking of the metering valve 34, and to renderit sensitive to slight changes in the speed of the governor the valve 34is positively rotated by the gear 64 through a spider 164, the ends ofwhich are positioned in a pair of the slots 152 of the gear 64. Avgenerally rectangular yaperture 166 .at the center of the spider 164engages a rectangular tang 168 on the end of the metering valve 34 toprovide driving connection therebetween.

As seen in FIG. 1, the gear 64 is provided with yan apertured elongatedhub 170 which projects in the direction of the segments 150 to the endof sleeve 142 to improve the stability of the gear 64 on the sleeve 142.Since the hub is an integral part of the gear 64 it further provides arotatable positive stop to limit the inward radial movement of theweights 154.

As shown in FIG. 5, each of the axially extending segments 150 of thegear 64 have, on their outer surfaces, a pair of gear teeth 172. Theinner surface of the cap member 148 provides a plurality Iof radialinwardly raised radial ribs 174 each having a centrally disposed tooth176. When the gear 64 and the cap member 148 .are assembled to form thecage for the weights 154, the tooth 176 is positioned between the pairsof teeth 172 of one of the segments 150 to provide a positive drive forthe cap member 148 from the gear 64 without the need for any additionalparts. The number of ribs 174 correspond with the number of gearseg-ments 150 and are angularly spaced apart by slots 178 which arealigned with the slots 152 between the gear segments for receiving thepivot ends of the governor weights 154.

Another feature of this invention is that the distance betweendiametrically opposed upper surfaces of the ribs 174 is slightly lessthan the outer diameter of the gear teeth 172 so that the segments l150must be deflected inwardly a small amount during the assembly of the cap148 on the gear 64. With this arrangement, the resiliency of the gearsegments 150 positively and accurately mounts the cap memberconcentrically on the governor Weights with the gear and frictionallymaintains the cap member 148 assembled on the gear 64.

The adjusting screw 144 permits the axial adjustment of the meteringvalve 34 when the governor is at rest so that the metering port is justfully open and will be reduced in size as the weights begin to pivotoutwardly. In this way the `full travel of the governor weights isavailable for controlling the metering port 41 despite manufacturingvariations in the manufacture of the governor assembly.

It is believed that the operation of the governor of the 'presentinvention will be apparent from the foregoing description taken togetherwith the following explanation.

As has previously been described, the governor weights are arranged topivot about their apexes 163 responsive to the rotation of the governorcage formed by the `gear 64 and the cap member 148. The centrifugalforce developed by the Weights is directed axially through the thrustwasher 160 to move the metering valve 34 to the right against the biasof spring 29 to control the amount the metering port 41 is open. Thepassage I190 interconnects the chamber containing spring 29 with theannulus 192 around the opposite end of the metering valve 34 so thatfuel in the spring chamber does not aiect the axial position of themetering valve 34. The left end of the spring 29 engages the meteringvalve 34 and the right end thereof engages a Spool 180 having a centralshank 182 surrounded by a light idle control spring 184. The centralshank '182 of spool 180 bottoms against washers 188 when the throttle 25is moved above idle speed and a throttle control member 186 engaging theend of idle control spring through any lsuitable low friction thrustconnection such as washers 188 to accommodate the rotation of the spring29, spool 180 and spring 1-84 with the metering valve 34.

As will be apparent to persons skilled in the art, various modificationsand adaptations of the structure above described will become readilyapparent without'departure from the spirit and scope of the invention,the scope of which is defined in the appended claims.

I claim:

1. A fuel pump governor comprising a gear, one end of which is segmentedto provide a plurality of angularly spaced slots around the peripherythereof, a cap member engaging the segments of said gear for rotationtherewith, a plurality of weights mounted selectively in at least someof said slots for pivotable movement during the rotation of the governorwhereby said gear and said cap member form a cage for guiding thepivotable movement of said weights.

2. A device as recited in claim 1 wherein said gear has outwardlydirected teeth from one end to the other said cap member has matinginwardly directed teeth to provide a driving connection therebetween.

3. A device as recited in claim 1 whereinthe adjacent segments formingsaid one end of said gear have parallel sides for guiding the weightsfor radial movement.

4. A device as recited in claim 1 wherein the segments forming said oneend of said gear resiliently engage said cap member.

5. A device as recited in claim 1 wherein said gear is provided with acentral hub spaced inwardly from said segmented end thereof for limitingthe inward movement of the free end of said weights.

6. A device as recited in claim 1 wherein said gear provided with anapertured central hub projecting in th direction of said segmented end,and a stub shaft receive within said aperture for mounting said governorfc rotation.

7. A device as recited in claim 2 wherein each gea segment has a pair ofteeth for straddling a mating toot on said cap member.

8. A device as recited in claim 6 wherein a contr( member extendsthrough an aperture in said stub s'ha and is mounted for axial movementin response to th movement of said governor weights.

9. A device as recited in claim 8 wherein a spider hai ing ends disposedin said slots of said gear engages sai control member for positivelyrotating the same.

10.' A device as recited in claim 9 in combination wit a housing forsaid governor, and adjustable means o said housing providing a reactionsurface for said ca member for adjusting the axial position of saidcontr( member.

References Cited UNITED STATES PATENTS 1,539,291 5/1925 Bentley 73-552,114,813 4/1938 Reynolds et al. 73--53 2,538,982 1/1951 Roosa 73-53JAMES I. GILL, Prima/'y Examiner.

ROBERT S. SALZMAN, A sssmnr Examiner.

